LBS are becoming more and more popular in mobile stations. These services are typically based on three different positioning technologies: GPS (Global Positioning System), position triangulation with the help of RBS:s (radio base stations) and positioning with the help of communications network cell-ID (cell identity or cell name/number), where the cell-ID typically is a unique number of a cell of GSM (Global System for Mobile Communications)/UMTS (Universal Mobile Telecommunications System)/LTE (Long Term Evolution) for a given operator. Each positioning technology has advantages and disadvantages. GPS gives a relatively exact position under favourable conditions, but requires dedicated hardware, i.e. a GPS receiver circuit, on the client side and is generally not working indoors or in tunnels. Network Cell-ID based positioning, where a mobile station knows which network cell in the mobile communications network it is closest to, generally requires no extra hardware. However a database of mappings between network cell-IDs and a geographical area is needed. In comparison with GPS, positioning systems that utilize network cell-IDs typically does not give as high positioning accuracy and the database needs to be created and updated, which could be especially cumbersome if the database owner is not the network owner/operator. Triangulation with the help of RBS:s typically gives a better accuracy, but far from the accuracy typically given through GPS and requires support from the network owner/operator.
There exist a lot of different applications exploiting positioning systems and a common feature is POIs (points of interest). This feature basically means that certain attractions that are considered to be of interest to a user are displayed on a map in a UE, such as a navigation system in a vehicle or a mobile station. For instance, modern navigation systems for vehicles are typically adapted to show on a displayed map area all gas stations as small gas pump icons. Another beneficial functionality of LBS is the possibility to trigger events/actions based on the location of the UE. A problem when implementing this kind of functionality is that the UE should constantly be aware of its location in order to trigger events. To know its position the UE must either utilize GPS technology or any other satellite based positioning system, such as GLONASS (Global Navigation Satellite System) and GALILEO, or make frequent connections to a server in order to either lookup its current network Cell-ID in a database of Network Cell-IDs mapped to geographic positions or request to be positioned by a radio base triangulation service. As stated before, GPS technology does not work appropriately indoors and frequent connections to a network server demands network- and UE capacity. Furthermore the battery powering the UE is discharged faster.
WO-2007/051223-A1 discloses a system which may enable service differentiation based on current location. For example, if a mobile station subscriber is in a home zone, which may be a smaller zone than a network cell, the tariffs of services utilized by the mobile station may be smaller than if the subscriber is outside the home zone. According to the system a zone may be stored in a SIM (Subscriber Identity Module) card, which in practice makes the system rely on integration with an operator network.